In connection with motor vehicles such as passenger cars of the station wagon kind, i.e. a vehicle which comprises a passenger compartment which is integrally shaped with a relatively large rear luggage compartment, it is known from prior art to shape this luggage compartment so that it can house an additional seat. Such an extra seat can then be arranged behind the regular rear seat, and can be so arranged that it faces backwards, i.e. so that a person in the extra seat will sit with his face towards the rear end of the vehicle, and thus have his back towards the front of the vehicle. The purpose of such an extra seat is to utilize the relatively large luggage compartment in a station wagon for transport of passengers as well, in those cases where it is not used for transporting large pieces of cargo.
According to prior art, such an extra seat normally comprises a cushion part and a back rest part which can be arranged detachably or permanently in the luggage compartment. In order to increase the flexibility of the vehicle, the extra seat can be so arranged that its cushion part can be raised when not in use.
Due to the limited amount of space which normally is available in the luggage compartment of a station wagon, the above-mentioned extra seat is normally utilized for passengers with a certain maximum body weight and length, i.e. usually for children and adolescents. A child travelling in such an extra seat is given a raised level of security as compared with, for example, if the child instead had been sitting without a safety belt in the rear seat or in the luggage compartment.
Although the above-mentioned extra seat thus provides good safety for passengers during transport, it can in connection with certain types of vehicles cause certain problems, particularly regarding protection for passengers in case of collisions or crashes. In particular, when hit from behind there is a risk that parts of the rear structure of the vehicle, for example the rear window, will be pushed into the vehicle in the direction of those sitting in the extra seat. This can of course injure the passengers, for example if the rear window hits the head or torso of the passengers, or if glass shards from the rear window hit the passengers.
In order to solve the above-mentioned problem, it has previously been attempted to reinforce the structure of the rear part of the vehicle, in order to thus prevent invasion of the luggage compartment when for example being hit from behind. In this way, it is for example possible to try to prevent the rear window of the vehicle from being pushed inwards and hitting a passenger in the extra seat. Although this in principle is an efficient way of solving the above-mentioned problem, it has limits, since it for reasons of cost and design is not possible to reinforce the structure of the body of the vehicle beyond certain limits. This in turn is due to higher demands regarding, for example, the weight of the vehicle and its fuel optimization, thus causing demands for new solutions to the said problem as an alternative to only reinforcing the structure of the vehicle which would cause an increased weight of the vehicle.